

How to Install Apache Benchmark on CentOS (bash: ab command not found)
Because I’m keep forgetting this and probably many of you might also need this info, I decided to post it on my blog. Lately I was doing some benchmark tests on different servers. On one of the servers (running on CENTOS 6.8) I was using the Apache Benchmarking tool and was getting this error:
bash: ab command not found
After doing some investigation and online research I found out httpd was missing so I tried to install it. The installation failed. From further investigation I found out that I have to editing the yum.conf file.
I’m a web developer, but don’t have much experience with configuring servers, so it took me a while to figure everything out. Anyways, I will show you step by step what you should do in order to install AB benchmark on your CENTOS 6.8 server:
Connect via SSH to the server using Putty.
Run the following command to configure yum.conf
vi /etc/yum.conf
The Result
exclude=bind-chroot courier* dovecot* exim* filesystem httpd* mod_ssl* mydns* mysql* nsd* php* proftpd* pure-ftpd* spamassassin* squirrelmail*
Now you have to remove http* from the exclude list.
Type the following command to save and exit:
:wq
Now install httpd using the following command line:
yum -y install httpd
This will take few seconds and will get a notification whether the installation was successful or not. After installing httpd you need to run the following command for benchmarking:
ab -n 1000 -c 10 http://google.com/
The result:
Benchmarking google.com (be patient).....done
Server Software: gws
Server Hostname: google.com
Server Port: 80
Document Path: /
Document Length: 219 bytes
Concurrency Level: 10
Time taken for tests: 0.030 seconds
Complete requests: 10
Failed requests: 0
Write errors: 0
Non-2xx responses: 10
Total transferred: 5400 bytes
HTML transferred: 2190 bytes
Requests per second: 332.06 [#/sec] (mean)
Time per request: 30.115 [ms] (mean)
Time per request: 3.011 [ms] (mean, across all concurrent requests)
Transfer rate: 175.11 [Kbytes/sec] received
Connection Times (ms)
min mean[+/-sd] median max
Connect: 1 1 0.3 1 1
Processing: 13 14 0.4 14 14
Waiting: 13 14 0.5 14 14
Total: 13 15 0.6 15 16
Percentage of the requests served within a certain time (ms)
50% 15
66% 15
75% 15
80% 15
90% 16
95% 16
98% 16
99% 16
100% 16 (longest request)
Done!
Hope this has helped you and next time if I forget how to install the AB (Apache Benchmark) on a web server, this tutorial will help me remember.